Matrix-retainer.



.F. M. DEAN.

MATRIX RETAINER.

APPLICATION FILED JAN-19. 1915.

Patented Sept. 7, 1915.

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FRANCIS M. DEAN, OF ANAOORTES, WA SHINGTON.

MATRIX-RETAINER.

1 Specification of Letters Patent.

Application filed January 19, 1915. Serial No. 3,104.

To all whom it may concern:

Be it known that I, FRANCIS M. Drama citizen of the United States, residing. at Anacortes, in the county of Skagit and State of lVashington, have invented certain new and useful Improvements in Matrix-Retainers, of which the following is a specification, reference being had to the accompanying drawings. 1

This invention relates to an improved matrix retainer, such'as is commonly used by dentists for clamping or holding a tooth my invention consists in the novel features" of construction, comblnation, and arrange ment of parts to be hereinafter more fully described, claimed, and illustrated in the accompanying drawing, in which,

Figure 1 is a perspective view of my improved matrix retainer, showing the same in closed position 5 Fig. 2 is a side elevation, the clamping jaws being open; and Fig. 3 is a longitudinal section of the device.

Referring in detail to the drawing, 5 designates spaced substantially triangularshaped plates, which constitute the bearing for the operating levers later referred to. A rod, indicated at 6, is disposed centrally between these two bearing plates and projects outwardly therefrom to a considerable dis-- tance beyond their wider ends. This rod is rigidly held in place by means of the rivet 7 which connects the triangular-shaped bearing plates at their apexes.

8 designates the operating levers which are identical in form, and are pivotally mounted between the corners of the bearing plates 5 upon the connecting rivets 9. Adj acent to these latter ends of the levers, the same are formed with the laterally projecting arms 10. The extremities of the longer arms of the levers 8 are disposed at right angles to the arm and extended in relatively Patented Sept. '7, 1915.

opposite directions, as at 11, to provide suitable finger pieces, whereby said levers may" be conveniently actuated. The gripping or retaining jaws;12 are longitudinally curved and arranged in opposed relation upon opposlte sides of the rod 6. At the inner ends of said jaws, the same are reversely curved and formed with obliquely disposed extensions 18, the extremities of which are bifurcated and plvotally connected as at 14, to

the shorter arms 10 of the operating levers.

The upper free ends of the retaining jaws 12 are preferably formed with the terminal spurs or gripping points 15. The reverselycurved innerend portions of these aws are connected upon opposite sldes by the links 16, said links being disposed upon opposite sides of the central rod 6.

In the operation of my improved matrix retainer as above described, assuming that the jaws have been opened to the position shown in Fig. 2, the matrix is arranged between the same, and the operator swings the levers 8 downwardly and inwardly toward each other. "The arms 10 of said levers are jaws 12 moved inwardly toward'each other untiltlie spurs 15 securely grip the matrix and retain the same in position between the jaws. The central rod 6 forms a guide for the jaws in their opening and closing movements. When the links 16 are disposed below the central portion of this rod, the pivots connecting said links with the jaws are so located with respect to the pivoted ends of the jaw extensions 13, that said jaws cannot spread or separate. Such separation can only be effected by movement of the levers 8 outwardly away from each other. In this manner, it will be seen that I have produced a very simple and effective matrix retainer, which may be easily and quickly operated to securely grip and retain the matrix. I have.

spects and the. device also made in a number of different sizes, without departing from the essential features or sacrificing any. of the advantages of the invention as claimed.

Having thus fully described my invention, what I desire to claim and secure by Letters Patent is 1. A device of the character described including opposed retaining jaws having obliquely disposed extensions formed on one end, a bearing, opposed levers pivotally mounted on said'bearing and provided with laterally extending arms, connected to the extensions of the respective retaining jaws, and link connections between the inner ends of said, jaws at their juncture with said extensions. 1

2. A deviceof the character described including opposed retaining jaws having obliquely disposed extensions attheir inner ends, a bearing, opposed operating levers pivotally mounted on said bearing, each of said levers being provided with a laterally disposed arm on ,its pivoted end, the arms ofsaid levers being connected to the extensions of the respective jaws, a longitudinally extending rod fixed at one end to said bearing, and link connections between the jaws at their inner ends disposed upon opposite sides of said rod.

3. A dental matrix retainer including a bearing, opposed retaining jaws, means in- 1 dependent of the bearing connecting said jaws forrelative movement, and a pair of longitudinally with respect to said bearing and in one position loclcthe jaws closed upon the matrix.

dental matrix retainer including a b dy, Opp s e a ning a s, m s independent of the body connecting said jaws to each other, and levers pivotally mounted upon saidbod-y and having pivot connections withthe respective jaws at their inner ends, said levers moving the jaws in unison longitudinally with respect to the body and in one position disposing the pivot connections between the jaws and the levers with respect to the, pivot connections, between the levers and the body whereby the jaws are locked in their closed position upon the matrix.

In testimony whereof I hereunto affix my signature in the presence of two witnesses.

FRANCIS M; DEAN.

itn sses FRANK R- NORVELL, J. W. NORVELL.

Copiesof this patent may be obtained for five cents each, by addres ing the Commissioner or'lfatents,

' i I Washington, 11. 0 i 

